A couple of times I've seen flargle recommend a hard training day on the day after a race. As I was riding to work this morning I was surprised to notice that my legs felt pretty good, so I rode my commute like a time trial (if a time trial course were littered with stop signs and traffic lights) and ended up with a new personal best (as silly as I know it is to track such a thing for a commute) and was completely jelly-legged when I got there. (FWIW, commuting is my main time for training rides during the week, so whatever I do has to be squeezed into the 10-12 miles each way to and from work.)
So I'm wondering, does anyone else do a hard workout the day after a race? Should I just pick this as whatever type of ride I need work on, or is there something specific that would benefit me most in this slot? What type of benefit should I expect to see from doing this?